[PATCH] usb: dwc3: qcom: Check for L2 only when suspending a host with wakeup

[PATCH] usb: dwc3: qcom: Check for L2 only when suspending a host with wakeup

[Fabricio Akio via B4 Relay]

From: Fabricio Akio <fabricioakio@gmail.com>

In peripheral mode the core disconnects and powers the PHY off before
the glue suspends, so the link never enters L2 and every system
suspend logs "HS-PHY not in L2". Check only for a host with wakeup,
the one case that parks the PHY in L2.

Signed-off-by: Fabricio Akio <fabricioakio@gmail.com>
---
Tested on a Motorola Moto X4 (XT1900-6, SDM630) with the sdm660-mainline
7.2.3 tree, in peripheral mode with the cable attached: the "HS-PHY not
in L2" message appears on every system suspend without this patch, and
not over three consecutive cycles with it. Host mode is untested, since
this board runs the controller in peripheral mode. The board binds
dwc3-qcom-legacy, so the same change in dwc3-qcom.c is build-tested
only. Applies unchanged to next-20260928.
---
 drivers/usb/dwc3/dwc3-qcom-legacy.c | 16 ++++++++++++----
 drivers/usb/dwc3/dwc3-qcom.c        | 16 ++++++++++++----
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-qcom-legacy.c b/drivers/usb/dwc3/dwc3-qcom-legacy.c
index d3fad0fcfdac..ba3f70dea4ab 100644
--- a/drivers/usb/dwc3/dwc3-qcom-legacy.c
+++ b/drivers/usb/dwc3/dwc3-qcom-legacy.c
@@ -431,10 +431,18 @@ static int dwc3_qcom_suspend(struct dwc3_qcom *qcom, bool wakeup)
 	if (qcom->is_suspended)
 		return 0;
 
-	for (i = 0; i < qcom->num_ports; i++) {
-		val = readl(qcom->qscratch_base + pwr_evnt_irq_stat_reg[i]);
-		if (!(val & PWR_EVNT_LPM_IN_L2_MASK))
-			dev_err(qcom->dev, "port-%d HS-PHY not in L2\n", i + 1);
+	/*
+	 * Only a host with wakeup enabled keeps the HS PHY powered and parks
+	 * it in L2 across suspend. A peripheral disconnects from the bus and
+	 * powers the PHY off first, so its link never enters L2.
+	 */
+	if (dwc3_qcom_is_host(qcom) && wakeup) {
+		for (i = 0; i < qcom->num_ports; i++) {
+			val = readl(qcom->qscratch_base + pwr_evnt_irq_stat_reg[i]);
+			if (!(val & PWR_EVNT_LPM_IN_L2_MASK))
+				dev_err(qcom->dev, "port-%d HS-PHY not in L2\n",
+					i + 1);
+		}
 	}
 
 	for (i = qcom->num_clocks - 1; i >= 0; i--)
diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
index ac68b4218b56..e0920da280ce 100644
--- a/drivers/usb/dwc3/dwc3-qcom.c
+++ b/drivers/usb/dwc3/dwc3-qcom.c
@@ -343,10 +343,18 @@ static int dwc3_qcom_suspend(struct dwc3_qcom *qcom, bool wakeup)
 	if (qcom->is_suspended)
 		return 0;
 
-	for (i = 0; i < qcom->num_ports; i++) {
-		val = readl(qcom->qscratch_base + pwr_evnt_irq_stat_reg[i]);
-		if (!(val & PWR_EVNT_LPM_IN_L2_MASK))
-			dev_err(qcom->dev, "port-%d HS-PHY not in L2\n", i + 1);
+	/*
+	 * Only a host with wakeup enabled keeps the HS PHY powered and parks
+	 * it in L2 across suspend. A peripheral disconnects from the bus and
+	 * powers the PHY off first, so its link never enters L2.
+	 */
+	if (dwc3_qcom_is_host(qcom) && wakeup) {
+		for (i = 0; i < qcom->num_ports; i++) {
+			val = readl(qcom->qscratch_base + pwr_evnt_irq_stat_reg[i]);
+			if (!(val & PWR_EVNT_LPM_IN_L2_MASK))
+				dev_err(qcom->dev, "port-%d HS-PHY not in L2\n",
+					i + 1);
+		}
 	}
 	clk_bulk_disable_unprepare(qcom->num_clocks, qcom->clks);
 

---
base-commit: 6375e61c01e93e35ee7acd336a689ac1fae4b509
change-id: 20260928-dwc3-qcom-l2-check-e3b55acefb62

Best regards,
--  
Fabricio Akio <fabricioakio@gmail.com>

Re: [PATCH] usb: dwc3: qcom: Check for L2 only when suspending a host with wakeup

[Huang Wei]

Hi Fabricio,

This matches what I'd expect from the PHY behaviour - in peripheral
mode the device disconnects before the glue suspends, so there is no
link left to park in L2, and the unconditional check is just log noise
on every suspend. Restricting it to the host-with-wakeup case that
actually relies on L2 retention looks right.

The untested host path is low risk in a specific way: for host with
wakeup the check runs exactly as before, so the patch only silences
the cases where L2 is not expected. And since the runtime PM paths
pass wakeup unconditionally, host runtime suspend still gets the
check, which seems to be the intended behaviour.

Tested on real hardware in the mode that was noisy - nice.

Reviewed-by: Huang Wei <huangwei@kylinos.cn>

Thanks,
Huang Wei

Re: [PATCH] usb: dwc3: qcom: Check for L2 only when suspending a host with wakeup

[Thinh Nguyen]

On Mon, Sep 28, 2026, Fabricio Akio via B4 Relay wrote:
> From: Fabricio Akio <fabricioakio@gmail.com>
> 
> In peripheral mode the core disconnects and powers the PHY off before
> the glue suspends, so the link never enters L2 and every system
> suspend logs "HS-PHY not in L2". Check only for a host with wakeup,
> the one case that parks the PHY in L2.
> 
> Signed-off-by: Fabricio Akio <fabricioakio@gmail.com>
> ---
> Tested on a Motorola Moto X4 (XT1900-6, SDM630) with the sdm660-mainline
> 7.2.3 tree, in peripheral mode with the cable attached: the "HS-PHY not
> in L2" message appears on every system suspend without this patch, and
> not over three consecutive cycles with it. Host mode is untested, since
> this board runs the controller in peripheral mode. The board binds
> dwc3-qcom-legacy, so the same change in dwc3-qcom.c is build-tested
> only. Applies unchanged to next-20260928.
> ---
>  drivers/usb/dwc3/dwc3-qcom-legacy.c | 16 ++++++++++++----
>  drivers/usb/dwc3/dwc3-qcom.c        | 16 ++++++++++++----
>  2 files changed, 24 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-qcom-legacy.c b/drivers/usb/dwc3/dwc3-qcom-legacy.c
> index d3fad0fcfdac..ba3f70dea4ab 100644
> --- a/drivers/usb/dwc3/dwc3-qcom-legacy.c
> +++ b/drivers/usb/dwc3/dwc3-qcom-legacy.c
> @@ -431,10 +431,18 @@ static int dwc3_qcom_suspend(struct dwc3_qcom *qcom, bool wakeup)
>  	if (qcom->is_suspended)
>  		return 0;
>  
> -	for (i = 0; i < qcom->num_ports; i++) {
> -		val = readl(qcom->qscratch_base + pwr_evnt_irq_stat_reg[i]);
> -		if (!(val & PWR_EVNT_LPM_IN_L2_MASK))
> -			dev_err(qcom->dev, "port-%d HS-PHY not in L2\n", i + 1);
> +	/*
> +	 * Only a host with wakeup enabled keeps the HS PHY powered and parks
> +	 * it in L2 across suspend. A peripheral disconnects from the bus and
> +	 * powers the PHY off first, so its link never enters L2.
> +	 */
> +	if (dwc3_qcom_is_host(qcom) && wakeup) {
> +		for (i = 0; i < qcom->num_ports; i++) {
> +			val = readl(qcom->qscratch_base + pwr_evnt_irq_stat_reg[i]);
> +			if (!(val & PWR_EVNT_LPM_IN_L2_MASK))
> +				dev_err(qcom->dev, "port-%d HS-PHY not in L2\n",
> +					i + 1);
> +		}
>  	}
>  
>  	for (i = qcom->num_clocks - 1; i >= 0; i--)
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index ac68b4218b56..e0920da280ce 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -343,10 +343,18 @@ static int dwc3_qcom_suspend(struct dwc3_qcom *qcom, bool wakeup)
>  	if (qcom->is_suspended)
>  		return 0;
>  
> -	for (i = 0; i < qcom->num_ports; i++) {
> -		val = readl(qcom->qscratch_base + pwr_evnt_irq_stat_reg[i]);
> -		if (!(val & PWR_EVNT_LPM_IN_L2_MASK))
> -			dev_err(qcom->dev, "port-%d HS-PHY not in L2\n", i + 1);
> +	/*
> +	 * Only a host with wakeup enabled keeps the HS PHY powered and parks
> +	 * it in L2 across suspend. A peripheral disconnects from the bus and
> +	 * powers the PHY off first, so its link never enters L2.
> +	 */
> +	if (dwc3_qcom_is_host(qcom) && wakeup) {
> +		for (i = 0; i < qcom->num_ports; i++) {
> +			val = readl(qcom->qscratch_base + pwr_evnt_irq_stat_reg[i]);
> +			if (!(val & PWR_EVNT_LPM_IN_L2_MASK))
> +				dev_err(qcom->dev, "port-%d HS-PHY not in L2\n",
> +					i + 1);
> +		}
>  	}
>  	clk_bulk_disable_unprepare(qcom->num_clocks, qcom->clks);
>  
> 
> ---
> base-commit: 6375e61c01e93e35ee7acd336a689ac1fae4b509
> change-id: 20260928-dwc3-qcom-l2-check-e3b55acefb62
> 
> Best regards,
> --  
> Fabricio Akio <fabricioakio@gmail.com>
> 
> 

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

Thanks,
Thinh